• Chuanhong Guo's avatar
    mtd: spinand: rework detect procedure for different READ_ID operation · f1541773
    Chuanhong Guo authored
    Currently there are 3 different variants of read_id implementation:
    1. opcode only. Found in GD5FxGQ4xF.
    2. opcode + 1 addr byte. Found in GD5GxGQ4xA/E
    3. opcode + 1 dummy byte. Found in other currently supported chips.
    
    Original implementation was for variant 1 and let detect function
    of chips with variant 2 and 3 to ignore the first byte. This isn't
    robust:
    
    1. For chips of variant 2, if SPI master doesn't keep MOSI low
    during read, chip will get a random id offset, and the entire id
    buffer will shift by that offset, causing detect failure.
    
    2. For chips of variant 1, if it happens to get a devid that equals
    to manufacture id of variant 2 or 3 chips, it'll get incorrectly
    detected.
    
    This patch reworks detect procedure to address problems above. New
    logic do detection for all variants separatedly, in 1-2-3 order.
    Since all current detect methods do exactly the same id matching
    procedure, unify them into core.c and remove detect method from
    manufacture_ops.
    
    Tested on GD5F1GQ4UAYIG and W25N01GVZEIG.
    Signed-off-by: default avatarChuanhong Guo <gch981213@gmail.com>
    Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
    Link: https://lore.kernel.org/linux-mtd/20200208074439.146296-1-gch981213@gmail.com
    f1541773
micron.c 2.89 KB